Plural speed transmission mechanism for mining machines



Dec. 28, 1954 L. E. SIMMONS 2,697,950

PLURAL SPEED TRANSMISSION MECHANISM FOR MINING MACHINES Original Filed 001;. 16, 1948 a Shets-Sheet 1 dZiomzey,

Dec. 28, 1954 E. SIMMONS PLURAL SPEED TRANSMISSION MECHANISM FOR MINING MACHINES 3 Sheets-Sheet 2 Original Filed Opt. 16, 1948 Dec. 28, 1954 1.. E. SIMMONS 2,697,950

PLURAL SPEED TRANSMISSION MECHANISM FOR MINING MACHINES 5 Sheets-Sheet 3 Original Filed Oct. 16, 1948 United States Patent PLURAL SPEED TRANSMISSION MECHANISM FOR MINING MACHINES Leon E. Simmons, Claremont, N. H., assignor to Joy Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Original application October 16, 1948, Serial No. 54,895. Divided and this application May 20, 1950, Serial No. 163,301

Claims. (Cl. 74-664) This invention relates to mining machines and more particularly to an improved feeding mechanism for a coal mining machine of the flexibly fed, longwall, floor type and embodying an improved plural speed transmission mechanism.

In a coal mining machine of the conventional longwall floor type the machine is usually fed over the mine floor both during maneuvering of the machine and during the kerf cutting operation by means of a feeding cable wound on a feed drum on the machine and attached at its free end to an anchor jack whereby when the cable is wound in by the drum the machine is moved bodily over the mine floor toward the point of anchor of the cable. Since the machine should be moved relatively rapidly during maneuvering and should be fed at a relatively low speed during the cutting operation, and the feeding speed during cutting should vary to suit different cutting conditions, it is desirable to provide driving means for the feed drum whereby the latter may be driven at a relatively high speed and through a relatively wide range of low speeds. In such a machine the cutter bar is usually pivotally mounted at the rear end of the machine frame to swing horizontally while the feed drum is usually arranged at the front end of the machine frame and the feed cable is attachable to the cutter bar hanger to effect swinging of the cutter bar on its pivotal mounting, and the feed cable is employed to position the bar and to swing the bar during cutting into a sumped position beneath the coal.

The present invention contemplates improvements over known types of coal mining machines in that an improved feeding mechanism is provided whereby a relatively wide range of feeding speeds, as well as extreme compactness and flexibility in operation, are attained. In accordance with the present invention the feeding mechanism embodies high and low speed drives for the feed drum of the machine, and the low speed drive is widely variable, and separate controls are provided for the high and low speed drives together with an interlock between the controls whereby simultaneous operation of the high and low speeds is prevented. The variable low speed drive embodies a variable speed ratchet and pawl type driving mechanism having a novel arrangement of parts, associated in a novel manner with elements of the high speed drive, and embodying a novel control for effecting speed changes.

An object of the present invention is to provide an improved coal mining machine. Another object is to provide an improved coal mining machine having an improved plural speed transmission mechanism. Yet another object is to provide an improved mining machine of the flexibly fed, floor type especially designed for use in accordance with the longwall method of mining. A further object is to provide an improved feeding mechanism embodying high and low speed drives and having improved interlocking means for preventing operation of one drive during the operation of the other. A still further object is to provide an improved mining machine mechanism of the variable speed, ratchet and pawl type and embodying improved speed changing means. These and other objects and advantages of the invention will, however, hereinafter more fully appear.

This application is a division of my copending application Serial No. 54,895, filed October 16, 1948, now matured into Patent No. 2,657,915, dated November 3, 1953.

In the accompanying drawings there is shown for purframe.

2,697,950 Patented Dec. 28, 1954- "ice poses of illustration one form which the invention may assume in practice.

In these drawings:

Fig. 1 is a horizontal sectional view, with parts shown in plan and the top cover removed, taken through a machine feeding mechanism constructed in accordance with an illustrative embodiment of the invention.

Fig. 2 is a longitudinal vertical sectional view taken substantially on the planes of line 22 of Fig. 1.

Fig. 3 is a detail horizontal sectional view taken substantially on the plane of line 3-3 of Fig. 2.

Figs. 4 and 5 are detail views showing the high and low speed feed control levers in different positions, and with parts in section to show the interlock between the control levers.

Fig. 6 is a longitudinal vertical sectional view taken substantially on the planes of line 66 of Fig. 1.

Fig. 7 is a horizontal sectional view taken substantially on the planes of line 77 of Fig. 6.

In this illustrative embodiment of the invention, as shown in the drawings, the coal mining machine includes a compact low height machine frame 1 slidable on its bottom 2 for movement over the floor of a mine and carrying the improved flexible feeding mechanism generally designated 3 driven by a motor 4 carried by the machine The machine frame comprises a feed frame section 5 and a motor frame section 6 and these frame sections are suitably rigidly united to provide a low compact unitary frame structure slidable over the mine floor. Carried by the feed frame section 5 is a large horizontal feed drum 7 on which a feed cable 8 is wound. Arranged near the four corners of the feed frame section 5 at the sides of the drum are conventional horizontal guide rollers 7a, 7b, 7c, and 7d, and the feed cable may be extended from the drum about different ones of these guide rollers in various directions during operation of the machine. The motor frame section 6 houses the motor 4, which is herein desirably an electric motor having its armature shaft 9 horizontally disposed and extending longitudinally of the machine frame at one side of and in parallelism with the longitudinal center of the frame, as shown in Fig. 1.

The improved feeding mechanism 3 comprises a spur pinion 10 (Fig. 1) keyed to the front end of the motor shaft 9 and meshing with and driving a spur gear 11 secured to a horizontal, longitudinally extending shaft 12 suitably journaled in the feed frame section 5. Secured to and driven by the shaft 12 is a worm 13 (Figs. 1, 2 and 7) meshing with and driving a worm wheel 14 (Fig. 6), the latter in turn secured to a circular enlargement 15 of a vertical shaft 16, the latter herein journaled in an upper ball bearing 17 supported by a bearing boss 17 integral with a top cover plate 18 and in a lower ball bearing 19 supported within a bearing boss 19 integral with a horizontal web 20 of the feed frame section. The shaft 16 has an eccentric portion or crank 21, to be later referred to- Formed on the upper portion of the shaft 16 is a spur gear 22 meshing with and driving a spur gear 23 having its hub journaled on a bearing 24 supported by a vertical shaft portion 25 of a swinging gear support 26. The support 26 comprises upper and lower support sections 27 and 28 secured together as by a screw 29 arranged within the shaft portion 25, and these support sections have hubs 30 swivelly mounted on the bearing bosses 17 and 19' (Fig. 6) to swing in horizontal planes. The gear 23 is adapted to mesh with and drive a spur gear 7 31 (Fig. 2) having its tubular hub journaled in upper internal gear 36 on the cable winding drum 7 of the feeding mechanism. The feed drum has a hub 37 journaled on vertically spaced ball bearings 38 supported by a vertical shaft 39 provided with a top flange 40 secured as by screws to the frame-web 20. A detachable bottom plate 41 is I secured to the feed frame section and has an upstanding boss 42 secured as by a screw to the shaft 39. The drum is arranged horizontally between the horizontal web 20 and the bottom plate 41, as shown in Fig. 2. It will be seen from the foregoing description that when the gear 23 is swung into mesh with the gear 31 the feed drum may be driven in cable winding direction at a relatively high speed suitable for machine-maneuvering through the motor pinion 10, spur gear 11, shaft 12., worm gearing 13, 14, shaft 16, spur gears 22 and 23, spur gear 31, shaft 34 and spur gear 35 meshing with the drum gear 36. The swingable support 26 may be swung on its pivotal mounting by an eccentric portion or crank 43 (Figs. 1, 6 and 7) received in a vertical slot 44 (Fig. 6) in the lower supportsection 28', and this crank is integral with an operating shaft 45- which is horizontally and longitudinally disposed and suitably journaled within bearing sleeves 46 supported within the feed frame section. Secured to this shaft is the hub 47 of an operating lever 48 herein conveniently located at the front end of the machine. Thus, the swingable support 26 may be swung to move the high speed gear 23 into and out of mesh with the gear 31. The operating lever 48 has a conventional releasable detent lock 48 for holding the same in its different positions of adjustment.

Now referring to the variable low speed drive for effecting rotation of the feed drum 7 in cable winding direction through a wide range of low feeding speeds suitable for cutting. it will be noted that pivotally connected to the crank 21 is one end of a connecting rod or link Si) (Figs. 6 and 7) which is pivotally connected at its opposite end to an oscillatory pawl carrier 51 of a step by step, ratchet and pawl device. This pawl carrier comprises upper and lower plates 52 and 53 provided with hubs 54 pivotally mounted on hearing sleeves 55 supported by the hub 56 of a toothed ratchet wheel 57 (Fig. 7). The hub of this ratchet wheel is keyed at 58 to the hub of the gear 31 (Fig. 2). The carrier plates 52. 53 are secured together by studs 59, 60. and the stud 59 supports bearing sleeves for the connecting rod 50. The other stud 60 supports bearing sleeves for a pivoted driver pawl 61 which is yieldingly urged toward en agement with the ratchet teeth by a coiled tension spring 62. A second pawl 63 (Fig. 7) suitably pivoted at 64 on the feed frame section is yieldingly'held in engagement with the ratchet teeth by a coiled tension spring 65'. The pawl 63 is reversely positioned with respect to the driver pawl 61 and serves to hold the ratchet wheel against reverse rotation during movement of the driver pawl into its different tooth engaging positions. A shield member 66 (Fig. 3) is rotatably mounted on a bearing sleeve 67 (Fig. 2) sup orted bv the hub of the ratchet wheel. and this shield is rotatable about an axis aligned with the axis of rotation of the ratchet wheel, and is adapted variably to shroud the ratchet teeth to varv the enga ement of the driver pawl 61 with the ratchet teeth to obtain variable speed drive. as later ex lained.

This shrouding-shield 66 is formed with a bevel gear segment 68' with which a bevel gear 69 formed on a horizontal lon itudinally extendin shaft 70 (Fi 2), meshes. The shaft 70 is iournaled within the feed frame section and has keyed thereto the hub 71 of an operating lever '72 likewise conveniently located at the front end f the machine. The lever 72 has a conventional r easable detent lock 72 for holding the same in its different positions. Thus. the shield may be turned by the lever to vary the action of the driver pawl on the ratchet wheel to rovide a wide range of intermittent variable speeds. The shield 66 has circumferentially spaced, smooth arcuate surfaces 73 and 74- (Fig. 3) so that when the lever 72 is in its position to release the ratchet-drive these surfaces respectively serve to hold the pawls 61 and 63 out of contact with the ratchet teeth. with the pawls riding back and forth along the surfaces 73 and 74 as the pawl carrier oscillates.

An interlock is provided between the high and low speed control levers 48 and 72 so that when the high speed drive is effective the low speed drive is maintained in its inoperative position, and vice versa. This interlock comprises a sliding locking bar or locking plunger 75 guided at 76 on the feed frame section and having tapered portions 77 at its opposite ends selectively receivable in appropriately located detent-notches 78 and 79 in the lever hubs. This shiftable locking bar is of such a length that it must be received in one notch before it can be released from the other notch. In Fig. 5, the fast speed lever 48 is locked against movement by the locking bar 75 while the low speed lever 72 is free to be turned. In Fig. 4, the locking bar 7 is in its opposite position with the low speed lever 72 located in oif position and with the high speed lever 48 free to be turned. Thus, the concurrent connection of the high and low speed drives with the feed drumis prohibited.

The mode of operation of the improved feeding mechanism is as follows:

The machine may be fed over the mine floor during maneuvering by the feed cable 8 which is extended from the feed drum 7 and attached at its free end to an anchor jack, and wound in at a relatively high speed by the feed drum 7 through the high speed gearing. When the mining machine is properly positioned with respect to the coal face, the fast speed drive for the feed drum is disconnected and the feed cable is detached from the anchor jack and extended rearwardly from the drum around one of the guide rollers 7a or 7:1, along the face side of the machine and attached at its free end to the bar hanger frame, and as the feed drum is rotated at a slow speed to wind in the feed cable, the cutter bar is swung horizontally about its pivot relative to the machine frame into its sumped position within the coal. The cutter bar is then suitably locked rigidly to the machine frame, and the feed cable is detached from the bar hanger frame and is extended forwardly from the machine around one of the guide rollers 75 or 76 to an anchor jack located at the coal face in advance of the machine. The lever 72 is then positioned to connect the intermittent slow speed drive, with the ratchet set to obtain the desired feeding speed, and the feed drum is rotated to wind in the feed cable to advance the machine in an endwise direction forwardly along the coal face thereby to feed the cutter bar to cut a horizontal kerf beneath the coal. By varying the position of the shrouding-shield 66 the engagement of the driver pawl 61 with the ratchet teeth may be varied there by to vary the intermittent low speed drive of the feed drum between the maximum and minimum limits, as desired. Since the general mode of operation of a longwall coal mining machine is well known to those skilled in the art, further discussion of its mode of use is herein unnecessary.

As a result of this invention an improved coal mining machine is provided which is extremely flexible and ethcient in operation. The feeding mechanism, by the provision of the variable speed drive, may be operated to feed the machine in accordance with varying mining conditions, and the interlock between the high speed drive and the variable low speed drive prohibits concurrent connection of both drives with the feed drum. By the provision of the ratchet and pawl type variable speed drive a relatively wide range of intermittent feeding speeds is attained. The novel structural relation of the high and low speed drives lends itself to compactness, a highly desirable feature in a longwall type mine machine. Other advantages of the invention will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration, and that the invention may be. modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a transmission mechanism, a driven member, a motor driven gear having an eccentric crank rototable therewith, a support pivotally mounted to swing about the gear axis, a second gear carried by said swingable support and meshing with and driven by said gear, a third gear operatively connected to said driven member, means for swinging said support to move said second gear into mesh with said third gear, a ratchet and pawl device including an oscillatory pawl carrier swingable about the axis of said third gear, a connecting rod pivotally connected to said crank and to said pawl carrier for oscillating the latter, a rotatable shield coaxial with said ratchet device for preventing engagement of the pawl of said carrier with the ratchet teeth when said second and third gears are in mesh and for permitting engagement of the pawl with the ratchet teeth when said support is swung to move said second gear out of mesh with said third gear, and means for rotating said shield into its different positions.

2. in a transmission mechanism, a driven member, a motor driven gear having an eccentric crank rotatable therewith, a support swingable about the axis of said gear and carrying a gear meshing with and driven by said first gear, a third gear operatively connected to said driven member, means for swinging said support to move said second gear into mesh with said third gear, a ratchet device coaxial with said third gear, and a connecting rod for connecting said crank with said ratchet device, said ratchet device effecting intermittent low speed drive of said driven member when said support is swung into a posiltlion wherein said second and third gears are out of mes 3. A machine of the character disclosed, comprising a rotatable crank member having a crank pin, a driven member, an intermittent low speed drive for said driven member including a connecting rod engaging said crank pin, an oscillatory member actuated by said connecting rod and operatively connected to said driven member, and a high speed drive for said driven member including a gear coaxial with and rotatable at the same angular speed as said crank member, said high speed drive also including a gear meshing with and driven by said coaxial gear, and a frame pivoted to swing about an axis coincident with the axis of said coaxial gear and by which said driven gear is carried, and a third gear with which said driven gear is adapted to mesh in one position of said swingable frame and operatively connected to said driven member.

A machine as set forth in claim 3 wherein said oscillatory member of said intermittent low speed drive has its axis of oscillation coincident with the axis of rotation of said last mentioned gear.

5. A machine as set forth in claim 3 wherein swinging means is provided for said swingable frame including a rotatable crank engaged in a slot in the free end of said frame remote from the frame pivot.

6. In a transmission mechanism, the combination comprising a rotatable driving member, a rotatable element to be driven, high speed driving means for said element to be driven including an element driven by said driving member and arranged coaxially therewith, an element coaxial with said element to be driven and operatively connected thereto and a releasable connection between said two last mentioned elements including a swingable sup port having its pivotal axis aligned with the axis of rotation of said driving member and a connecting element carried by said swingable support, and an intermittent low speed driving means for said element to be driven including an oscillatory element having its axis of oscillation aligned with the axis of rotation of said element to be driven and a driving connection between said driving member and said oscillatory element.

7. A transmission mechanism as set forth in claim 6 wherein said connecting element carried by said swingable support is engageable with said other elements of said high speed driving means for effecting drive therebetween.

8. In a transmission mechanism, the combination comprising a rotatable driving member, a rotatable member to be driven, a support pivotally mounted to swing about an axis aligned with the axis of rotation of said driving member, a member carried by said support for effecting a connection between said members to eifect drive of said member to be driven at a relatively high speed, and an intermittent low speed drive for said member to be driven including an oscillatory member swingable about an axis aligned with the axis of rotation of said member to be driven, a driving connection between said driving member and said oscillatory member, and a rotatable member actuated by said oscillatory member and arranged coaxial with and operatively connected to said member to be driven.

9. A transmission mechanism as set forth in claim 8 wherein said oscillatory member carries a pawl and said rotatable member actuated by said oscillatory member has ratchet teeth with which said pawl engages.

10. A transmission mechanism comprising a rotatable crank member having a crank pin, a driven member, a connecting rod engaging said crank pin, an oscillatory member actuated by said connecting rod and through which said driven member may be intermittently driven at a relatively low speed, and a high speed drive for said driven member including a rotatable element coaxial with and rotatable at the same angular speed as said crank member, a rotatable member arranged coaxial with said driven member and a releasable connection between said two last mentioned members including a support pivoted to swing about an axis coincident with the axis of rotation of said element coaxial with said crank member and a connecting element carried by said swingable support for connecting said rotatable element and said member of said high speed drive in driving relation for effecting drive of said driven member at a relatively high speed.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date I 1,914,504 Holmes June 20, 1933 2,053,259 Baldwin Sept. 8, 1936 2,438,691 Armantrout Mar. 30, 1948 2,507,756 Boylan May 16, 1950 2,627,761 Recker Feb. -10, 1953 FOREIGN PATENTS Number Country Date 20,870 France July 23, 1919 

